If you have multiple smartphones, tablets, ebook readers, or any other USB powered devices, there’s a good chance your outlets are chock full of power adapters. But not all USB chargers are created equal—many power hungry devices, like the Apple iPad, require higher output for optimal charging. The Kanex DoubleUp Dual USB Charger ($49 direct) is a simple and effective solution for juicing up two power hungry devices with a single adapter. It’s powerful enough to charge two iPads at a time and has status LEDs to let you know when your devices are topped off. It’s just a bit pricey.
Design and Features
The minimally adorned DoubleUp has a simple and understated look, with a glossy plastic housing available in either black or white. At 3.38 by 2.5 by 1 inches (HWD), it’s significantly larger than your standard iPad charging adapter, but it does double duty with two 2.1-amp USB ports. A matte grey plastic band wraps around the edges, and around back are wall prongs that fold neatly into the body for compact travel. The prongs are also close to the top of the DoubleUp, so it won’t cover the outlet above it. Unfortunately, if you use a traditional power strip the DoubleUp’s relative heft will occupy multiple outlets, depending on the orientation and spacing.
There are two full-sized USB ports along the bottom edge, each delivering a 5-volt, 2.1-amp charge, and the DoubleUp has a total output power rating of 21 watts. Most tablets, like the iPad, and many newer smartphones require a 2.1-amp port for optimal charging. Each USB port also has a corresponding LED indicator that glows orange when charging and, with iOS devices, will glow green when close to fully charged (90 percent for iPhones and 98 percent for for iPads). It’s a nice feature that will tell you if your device is charged from afar. The DoubleUp is also surge protected and has a smart charging feature that notches the power output down when your devices are fully charged.
Performance and Conclusions
I conducted a quick test with an Apple iPad 2 and the newest fourth-generation iPad, both plugged into a single Kanex DoubleUp. After 30 minutes, the iPad 2 had gained a 20-percent charge, while the fourth-gen iPad gained 10 percent in the same time, which is comparable to the two respective Apple chargers on their own. Once the iPad 2 reached close to full charge, the LED went from orange to green. However, when the fourth-gen iPad reached 100 percent, the LED inexplicably went from orange to off. Kanex says this is to reduce the adapter’s power draw even further, but it’s worth noting if you have the fourth-gen iPad.
At $50, the Kanex DoubleUp isn’t cheap—Apple sells 12-watt single port USB chargers for $19 apiece. But if you have multiple high-power USB powered devices, the DoubleUp will undoubtedly be a useful, space-saving addition to your electronic arsenal. As far as USB chargers go, the Kanex DoubleUp is among the most feature packed, but you’ll pay a premium over your standard power adapter.
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Copyright © 2012 Ziff Davis, Inc